doc: Add docs

doc/man_docs.go

@@ -77,6 +77,8 @@ func GenManTreeFromOpts(cmd *cobra.Command, opts GenManTreeOptions) error {
 	return GenMan(cmd, &headerCopy, f)
 }
 
+// GenManTreeOptions is the options for generating the man pages.
+// Used only in GenManTreeFromOpts.
 type GenManTreeOptions struct {
 	Header           *GenManHeader
 	Path             string

doc/md_docs.go

@@ -126,6 +126,8 @@ func GenMarkdownTree(cmd *cobra.Command, dir string) error {
 	return GenMarkdownTreeCustom(cmd, dir, emptyStr, identity)
 }
 
+// GenMarkdownTreeCustom is the the same as GenMarkdownTree, but
+// with custom filePrepender and linkHandler.
 func GenMarkdownTreeCustom(cmd *cobra.Command, dir string, filePrepender, linkHandler func(string) string) error {
 	for _, c := range cmd.Commands() {
 		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {